package main

import (
	"bytes"
	"encoding/csv"
	"fmt"
	"log"
	"strings"
)

type Box struct {
	Addr string `json:"addr"`
	User string `json:"user"`
	Key  string `json:"key"`
	Name string `json:"-"`
	ssh  *SSHConfig
	zfs  *ZFSConfig
}

func (b *Box) ZFSTakeSnapshot(schedule, path string) (err error) {
	if *debugFlag {
		log.Printf("Box.ZFSTakeSnapshot : %s : Taking snapshot on %s for %s", b.Name, path, schedule)
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	timestamp := cfg.Now.Format("2006-01-02_15.04.05")
	name := fmt.Sprintf("%s-%s--%s", schedule, timestamp, cfg.Zfsnap[schedule])
	_, err = b.ssh.exec("zfs snapshot " + path + "@" + name)

	if err != nil {
		return
	}

	b.zfs.SnapshotAdded = true
	b.zfs.SnapshotList = append(b.zfs.SnapshotList, Snapshot(path+"@"+name))

	return
}

func (b *Box) ZFSGetLastSnapshot(path string) (last Snapshot, err error) {
	if *debugFlag {
		log.Printf("Box.ZFSGetLastSnapshot : %s : Start %s (%d snapshots)", b.Name, path, len(b.zfs.SnapshotList))
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	for _, v := range b.zfs.SnapshotList {
		if v.Path() == path {
			last = v
		}
	}
	if len(string(last)) == 0 {
		err = fmt.Errorf("no snapshot")
	}
	return
}

func (b *Box) ZFSIsLastSnapshot(src Snapshot) (is bool, err error) {
	if *debugFlag {
		log.Printf("Box.ZFSIsLastSnapshot : %s : Start %s", b.Name, string(src))
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	if *debugFlag {
		log.Printf("SSHConfig.isLastSnapshot : %s : Start %s", b.Name, string(src))
	}

	_, err = b.ZFSGetNextSnapshot(src)
	if err != nil {
		if err.Error() == "no snapshot" {
			is = true
			err = nil
		}
	} else {
		is = false
	}
	return
}

func (b *Box) ZFSGetFirstSnapshot(path string) (first Snapshot, err error) {
	if *debugFlag {
		log.Printf("SSHConfig.getFirstSnapshot : %s : Start %s", b.Name, path)
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	for _, v := range b.zfs.SnapshotList {
		if v.Path() == path {
			first = v
			return
		}
	}
	err = fmt.Errorf("no snapshot")
	return
}

func (b *Box) ZFSGetNextSnapshot(src Snapshot) (next Snapshot, err error) {
	if *debugFlag {
		log.Printf("Box.ZFSGetNextSnapshot : %s : Start %s", b.Name, string(src))
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	for id, v := range b.zfs.SnapshotList {
		if v == src {
			if len(b.zfs.SnapshotList) > id+1 {
				next = b.zfs.SnapshotList[id+1]
				if next.Path() == src.Path() {
					return
				} else {
					err = fmt.Errorf("no snapshot")
					return
				}
			} else {
				err = fmt.Errorf("no snapshot")
				return
			}
		}
	}
	err = fmt.Errorf("no snapshot")
	return
}

func (b *Box) ZFSUpdateSnapshotList() (err error) {
	if *debugFlag {
		log.Printf("Box.ZFSUpdateSnapshotList : %s : Start", b.Name)
	}

	b.zfs.M.Lock()
	if b.zfs.SnapshotDeleted || b.zfs.SnapshotAdded {
		b.zfs.SnapshotInitialized = false
	}
	b.zfs.M.Unlock()

	err = b.SnapshotInitialize()
	return
}

func (b *Box) ZFSGetSnapshotList() (snaps []Snapshot, err error) {
	if *debugFlag {
		log.Printf("Box.ZFSGetSnapshotList : %s : Start", b.Name)
	}

	err = b.SnapshotInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	snaps = b.zfs.SnapshotList
	return
}

func (b *Box) SnapshotInitialize() (err error) {
	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	if b.zfs.SnapshotInitialized {
		return nil
	}

	if *debugFlag {
		log.Printf("Box.SnapshotInitialize : %s : Start", b.Name)
	}

	b.zfs.SnapshotList = make([]Snapshot, 0)

	var buf *bytes.Buffer
	buf, err = b.SSHExec("zfs list -H -t snapshot -o name")

	csvReader := csv.NewReader(buf)
	csvReader.Comma = '\t'
	csvReader.FieldsPerRecord = 1

	csvData, err := csvReader.ReadAll()
	if err != nil {
		if *debugFlag {
			log.Printf("Box.SnapshotInitialize : %s : csvReader.ReadAll() : %s", b.Name, err)
		}
		return err
	}

	for _, rec := range csvData {
		b.zfs.SnapshotList = append(b.zfs.SnapshotList, Snapshot(rec[0]))
	}

	if *debugFlag {
		log.Printf("Box.SnapshotInitialize : %s : read %d zfs snapshots", b.Name, len(b.zfs.SnapshotList))
	}

	b.zfs.SnapshotInitialized = true
	b.zfs.SnapshotAdded = false
	b.zfs.SnapshotDeleted = false

	return nil
}

func (b *Box) ZFSUpdateList() (err error) {
	if *debugFlag {
		log.Printf("Box.ZFSUpdateList : %s : Start", b.Name)
	}

	b.zfs.M.Lock()
	if b.zfs.ZFSDeleted || b.zfs.ZFSAdded {
		b.zfs.ZFSInitialized = false
	}
	b.zfs.M.Unlock()

	err = b.ZFSInitialize()
	return
}

func (b *Box) ZFSIsZFS(path string) bool {
	if *debugFlag {
		log.Printf("Box.ZFSIsZFS : %s : Start %s", b.Name, path)
	}

	err := b.ZFSInitialize()
	if err != nil {
		return false
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	if _, ok := b.zfs.ZFSMap[path]; ok {
		return true
	}
	return false

}

func (b *Box) ZFSCreateZFS(path string) (err error) {
	if *debugFlag {
		log.Printf("Box.ZFSCreateZFS : %s : Start %s", b.Name, path)
	}

	err = b.ZFSInitialize()
	if err != nil {
		return
	}

	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	p := strings.Split(path, `/`)
	var base string
	for _, d := range p {
		if base == "" {
			base = d
		} else {
			base = base + `/` + d
		}
		if _, ok := b.zfs.ZFSMap[base]; !ok {

			if *debugFlag {
				log.Printf("Box.ZFSCreateZFS : Creating %s:%s", b.Name, base)
			}

			_, err = b.SSHExec("zfs create -o mountpoint=none " + base)
			if err != nil {
				if *debugFlag {
					log.Printf("Box.ZFSCreateZFS : %s : SSHExec : %s", b.Name, err)
				}
				return
			}

			b.zfs.ZFSMap[base] = "none"
			b.zfs.ZFSAdded = true
		}
	}

	return
}

func (b *Box) ZFSInitialize() (err error) {
	b.zfs.M.Lock()
	defer b.zfs.M.Unlock()

	if b.zfs.ZFSInitialized {
		return nil
	}

	if *debugFlag {
		log.Printf("Box.ZFSInitialize : %s : Start", b.Name)
	}

	b.zfs.ZFSMap = make(map[string]string)

	var buf *bytes.Buffer
	buf, err = b.SSHExec("zfs list -H -o name,mountpoint")

	csvReader := csv.NewReader(buf)
	csvReader.Comma = '\t'
	csvReader.FieldsPerRecord = 2

	csvData, err := csvReader.ReadAll()
	if err != nil {
		if *debugFlag {
			log.Printf("Box.ZFSInitialize : %s : csvReader.ReadAll() : %s", b.Name, err)
		}
		return err
	}

	for _, rec := range csvData {
		b.zfs.ZFSMap[rec[0]] = rec[1]
	}

	b.zfs.ZFSInitialized = true
	b.zfs.ZFSAdded = false
	b.zfs.ZFSDeleted = false

	return nil
}

func (b *Box) SSHExec(cmd string) (buf *bytes.Buffer, err error) {
	buf, err = b.ssh.exec(cmd)
	return
}